More than 200 civilians have been killed since Monday in Syrian regime airstrikes on parts of rebel-held Eastern Ghouta near Damascus, The Guardianreported[1].

The neighborhood has been surrounded by Syrian forces for more than four years, with the siege intensifying in May when regime troops, backed by Iran and Russia, conducted a large-scale offensive.

“Ghouta is drowning in blood,” said a doctor in Arbeen, one of the towns in the region. “There is no safe place in Ghouta,” added Raed Srewel, a journalist based in Douma, another town in the area. “You can describe it with this saying we have: “On top of death, the graves are too small.”

According to the Syrian Observatory for Human Rights, a U.K.-based monitoring group, 59 civilians, including 15 children, have been killed on Thursday alone in eastern Ghouta.

The neighborhood was one of several so-called de-escalation zones agreed last year by Russia, Turkey and Iran. However, airstrikes escalated in recent days after a Russian warplane was grounded over the weekend in the rebel-held northwestern province of Idlib.

A United Nations commission, tasked with investigating war crimes and crimes against humanity in Syria, earlier this week condemned the upsurge of violence in Idlib and Ghouta, saying they “make a mockery” of the de-escalation agreement.

“What is happening in eastern Ghouta is not simply a humanitarian crisis because aid is denied. These sieges involve the international crimes of indiscriminate bombardment and deliberate starvation of the civilian population,” said Paulo Pinheiro, the chair of the commission

Russia on Thursday dismissed as “unrealistic” a UN appeal for a month-long humanitarian ceasefire in the war-stricken country. “That is not realistic,” Russian Ambassador Vassily Nebenzia told reporters. “We would like to see a ceasefire, the end of the war, but the terrorists, I am not sure, are in agreement,” he said.

The United States demanded an immediate end to the airstrikes, with the State Department saying in Washington: “These attacks must end now.”

With the backing of Iran and Russia, the Syrian regime has been able to regain control across the majority of Syria. An estimated 400,000 Syrians have been killed since the conflict erupted in 2011, according to the UN. More than 13.1 million Syrians are in need of humanitarian aid, including 6.1 million who have been displaced.